Issue with applied icons in macOS Sequoia

[KeirAnsell]

Describe the bug
Of course, macOS Sequoia is on it's first developer beta at the moment and so this could get resolved on Apple's side if the issue is there but I thought it worth filing anyway.

When applying System Folder icons in IconChamp, folders only display the top left quarter of the icon. I'm guessing it's probably something to do with the @2x variants.

This is an issue for both generic folders as well as the system folders (Desktop, Pictures etc).

This doesn't seem to affect User Folders icons applied through IconChamp, nor Drive Icons.

To Reproduce
Steps to reproduce the behavior:

1. On macOS Sequoia Developer Beta 1, apply some icons to the User Folders in IconChamp
2. View the folders with the updated icons.

Expected behavior
The icons should display correctly.

Screenshots

Desktop (please complete the following information):

• OS: macOS
• Version: 15 (Sequoia) Developer Beta 1

Additional context
SIP is disabled
Also worth noting that applying an icon to a folder by dragging the ICNS onto the icon in the Get Info window does apply the icon correctly.